a solar cooker has a parabolic section is y= 4/9 x^2. the greatest depth of the dish is 16 cm. (a) write down the quadratic equation (b) calculate the diameter of the dish

Answer 1

(-b+-(b^2-4ac)^.5)/(2a)

x=a=6, y=b=16

(-16+-(-16^2-4*6)^.5)/12

(-16+-(196-24)^.5)/12

(-16+-(13.11))/12

-.24083

-2.426

y=4/9*x^2, y=16

y/.444=x^2

(y/.444)^.5=x

(16/.444)^.5=6